The present invention relates to a rotation sensor for sensing a rotation of a rotating object.
Japanese Patent Application Publication No. 2000-310646 discloses an example of existing rotation sensors. In this example, the rotation sensor includes a sensor casing made of an insulating material, such as a resin material. The sensor casing includes a case member and a housing mounted on an open end of the case member. The case member houses electronic and magnetic components, such as a magnetic transducer element and a magnet. The magnetic transducer element is disposed at a position inside a closed end of the case member, and detects a rotation of an object rotating at a position outside the closed end of the case member. The housing is provided with a fixing part.
The rotation sensor of this example is fixed by the housing so that the closed end face of the case member is disposed close to the rotating object. The rotation of the object fluctuates a magnetic field existing at the position of the magnetic transducer element. The magnetic transducer element detects the fluctuation of the magnetic field, and thereby outputs information concerning the rotation of the object.